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Quantifying Single Microvessel Permeability in Isolated Blood-perfused Rat Lung Preparation
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In vivo determination of diffusive transport parameters in a superfused tissue
Michael F Flessner1, Ravi Deverkadra, Jeremy Smitherman
1Dept. of Medicine/Nephrology, Univ. of Mississippi Medical Ctr., 2500 North State St., Jackson, MS 39216, USA. mflessner@medicine.umsmed.edu
American Journal of Physiology. Renal Physiology
|May 11, 2006
Summary
This study links peritoneal tissue transport changes to structural alterations using mathematical modeling and rat experiments. Increased microvessel density directly correlates with enhanced mass transfer, diffusion, and water flux.
Area of Science:
- Physiology
- Biomedical Engineering
- Pharmacology
Background:
- Functional changes in tissue transport are hypothesized to relate to structural alterations.
- Understanding peritoneal transport is crucial for various medical applications, including dialysis and drug delivery.
Purpose of the Study:
- To investigate the relationship between peritoneal microvasculature structure and solute/water transport dynamics.
- To validate a combined mathematical modeling and in vivo experimental approach for measuring mechanistic transport changes.
Main Methods:
- Mathematical modeling of interstitial diffusion and microvascular removal.
- In vivo measurement of solute ([(14)C]mannitol) and water transport across the rat peritoneum using a chamber model.
- Assessment of microvessel density using FITC-dextran and quantitative autoradiography.
Main Results:
- Significant differences in water flux and mannitol mass transfer coefficient (MTC) were observed across groups with varying microvessel densities (norepinephrine, control, nitroprusside).
- Microvessel density directly correlated with water flux, MTC, capillary permeability, and tissue diffusivity.
- The study demonstrated a clear link between structural vascularity and functional transport parameters.
Conclusions:
- Peritoneal vascular density is a key determinant of mass transfer, diffusion, capillary permeability, and water flux.
- The developed methodology effectively measures mechanistic changes in peritoneal transport related to structural alterations.
- Findings support the hypothesis that structural changes underlie functional transport alterations in tissues.
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